Single Oral Dose Study of Atovaquone/Proguanil Hydrochloride Combination Tablets and Atovaquone Suspension

Inclusion Criteria: * Healthy as defined as being free from clinically significant illness or disease as determined by a responsible and experienced physician, based on a medical evaluation including medical history, physical examination, vital sign, laboratory tests and ECG. * Japanese healthy male between 20 and 55 years of age inclusive, at the time of signing the informed consent. * Body weight =\> 50 kg and BMI within the range 18.5- 25 kg/m2 * Non-smoker or ex-smoker having ceased smoking for at least 6 months. (inclusive). * ALT, alkaline phosphatase and bilirubin below the upper limit of normal (ULN) * Single QTcB\< 450 msec. * Vital sign within the following ranges; Systolic blood pressure: \< 90 mmHg or \> 140 mmHg, Diastolic blood pressure: \< 45 mmHg or \> 90 mmHg, Plus rate: \< 45 bpm or \> 100 bpm, Body temperature: 37.5 C * Capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the consent form. Exclusion Criteria: * A positive results of syphilis, HBs antigen, HCV antibody, HIV antibody and HTLV-1 antibody at the time of screening. * History of any cardiac diseases irrespective of with or without symptom. * An episode of cardiac syncope within one year before screening period. * History/evidence of clinically significant pulmonary diseases and hyper/hypo-thyroidism. * Current or chronic history of liver disease, or known hepatic or biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones). * A positive pre-study drug screen. * History of regular alcohol consumption exceeding, on average, 14 drinks/week for men (1 drink = 5 ounces (150 mL) of wine or 350 mL of beer or 1.5 ounces (45 mL) of 80 proof distilled spirits) within 6 months of screening. * The subject had participated in a clinical study or post-marketing study with an investigational or a non-investigational product during the previous 4 months preceding the administration of study medication of this study. * The subject had participated in a clinical study or post-marketing study with an investigational or a non-investigational product during the previous 4 months preceding the administration of study medication of this study. * Exposure to more than four new chemical entities within 12 months prior to the first dosing day. * Unable to refrain from the use of alcohol, prescription or non-prescription drugs, including vitamins, herbal and dietary supplements within 14 days or 5 half-lives (whichever is longer) prior to the first dose of study medication. * History of sensitivity to any of the study medications, or components thereof or a history of drug or other allergy excluding pollen allergy without current symptoms. * Where participation in the study would result in donation of blood or blood products in excess of 400 mL within a 4 month or 200 mL within 2 month. * Unwillingness or inability to follow the procedures outlined in the protocol. * Subject is mentally or legally incapacitated.